Former roller with cutting knife



April 28, 1954 G. AKE STAAF ETAL 3,130,886

FORMER ROLLER WITH cu'r'rmc KNIFE Filed July 10, 1961 2 Sheets-Sheet 1 INVENTOR GUSTAV BKE STAAF STIG ARNE MOLIN BY M T010.

ATTORNEY p 28, 1964 s. AKE STAAF ETAL 3,130,886

FORMER ROLLER WITH CUTTING KNIFE Filed July 10, 1961 2 Sheets-Sheet 2 o INVENTORS GUSTAV AKE STAAF STIG ARNE MOLIN BY mQg/ew, QA/LOL Tau ATTORNEY United States Patent M FQRMER RULLER WETH CUTTING KNIFE Gustav Ake Staaf, Hohultslatt, and Stig Arne Molin, Lagerfoshrulr, Sweden, assignors to Alstermo Bruks Alrtieholag, Hohultslatt, Sweden, a company of Sweden Filed July 10, 1961, Ser. No. 122,99$ Claims priority, application Sweden July 15, 1960 13 Clfiins. (Cl. 225-103) The present invention relates to former rollers for cardboard machines and especially to means for cutting up and taking off sheets from such rollers.

It has hitherto been customary to cut up the cardboard wound on the roller manually with a knife which is moved in a groove along a generatrix on the roller. This, however, is time-consuming and laborious. It has also been suggested to obtain a cut in the cardboard by means of a vigorous air current blown through a slot along a generatrix in the roller. To facilitate the taking off of the cardboard it has previously been suggested to arrange projectable plungers or air nozzles in the roller near the cut in the cardboard, so as to knock or blow out the edge of the cardboard, whereby the cardboard, as a rule detaches and drops from the roller, provided it is relatively thick and made of light ground pulp which is easily released from the roller surface. A thin cardboard of heavy ground smeary pulp can usually not be handled in this way, since due to the strong adherence to the roller surface it would then either be torn in rags or the plungers or the air current would pierce the pulp. Further it is previously known to cut the cardboard with a knife which is retractable into the roller and which may be pushed outwardly. Finally it is known to take off the cut sheet with the aid of a so-called air-knife, i.e. a fiat current of air obtained by blowing air through a slot parallel with the roller or cylinder.

It is the object of the invention to simplify and to improve the cutting of the sheet and its taking off from the former roller and especially to make this operation possible for practical application in making cardboard of smeary pulp or other types of pulp having a tendency strongly to adhere to the roller and/or which is fragile and easily torn in moist condition. This is especially the case in handling thin cardboard.

In order to obtain this object and other valuable advantages, the former roller of the present invention, which is rotatable in a given rotary direction, is provided with a knife, or pusher bar or plate, fitted in a groove in the roller and movable out of and into said groove substantially in a radial plane of the roller, and nozzles or openings arranged at the rear side of the pusher bar, with regard to said rotary direction, which can be connected with a source of pressurized gas, such as air, and means for cutting the cardboard wound on the roller along a line parallel with the pusher bar and situated at such a distance, preferably at least 8 mm. in front of said rear side of the pusher bar as to cause the edge flap of the sheet to be lifted by the projected bar up over the mouths of the nozzles or openings when in this stage pressurized air or the like is caused to blow out from these mouths, preferably as a jet blown away from the pusher bar in a direction in between the lifted sheet and the roller surface, preferably in a direction of at least 45 from said radial plane of the roller. The nozzles should be arranged to blow air in a direction between 0 and 90, preferably between 45 and 90 to the radial plane through the mouth of the nozzles.

In a preferred embodiment the means for cutting the cardboard is the pusher bar itself in combination with a groove in or near the peripheral edge of the pusher bar,

3,130,886 Patented Apr. 1 964 said groove being 1-5 mm., for example about 3 mm. broad, parallel with the pusher bar, and preferably at least 8 mm. in front of said rear side surface of the pusher bar. Said groove may be arranged in front of the pusher bar, for example in the roller surface near the pusher bar, or it may be constituted by a space between the front surface of the pusher bar and the adjoining Wall of the groove in the cylinder in which the bar is fitted. In this case a plate the thickness of which corresponds to the breadth of said space is fixed on the front surface of the pusher bar, the outer edge of said plate being below the outer edge of the pusher bar and constituting the bottom of the groove.

In an especially useful embodiment of the invention, the pusher bar has one or more cavities communicating, on the one hand, with a source of pressurized air and, on the other hand, with one or more nozzles or blow-out openings in the rear surface of the bar. These openings are uncovered in certain more or less projected positions of the bar. At its peripheral edge, the bar should be so broad, for example about 8 mm. or more, (properly speaking the distance between the rear surface of the bar and the groove in or at the bar) that the edge flap of the cut cardboard be lifted by the projected bar above the nozzles or openings in the rear surface of the bar when these are uncovered as the bar is pushed out. Preferably, the peripheral edge of the bar has the same radius of curvature as the surface of the roller. Suitably, on the front surface of the pusher bar there is an axial offset along the upper edge forming, when the bar is drawn back into the groove in the cylinder with its upper edge in level with the cylinder surface, an axial furrow in the surface of the roller.

As a matter of course the former roller may be provided with two or more pusher bars of the kind set forth above for cutting up the cardboard in several sheets, if desired. Suitably, the nozzles or openings in the rear surface of the bar or in the roller behind the bar may be arranged substantially along the entire length of the bar and they may be arranged so that they are uncovered or fed with pressurized air (actuated) at the same time along the entire length of the bar when the latter is pushed out, or so that they are uncovered at one part of the bar, for example at one or both ends thereof at first and then at other parts of the bar, for example little by little or continuously from one part to another. Instead of a series of small nozzles or openings there may be one or more slots arranged along the pusher bar.

The pusher bar may be actuated, i.e. pushed out of and retracted into its groove in any desired way but it is especially advantageous in the present case to actuate the bar with the aid of a pneumatic device. It is of course also possible to use a mechanical actuating device such as a cam follower movable along a cam for example. Said cam may be arranged at the ends of the former roller.

The invention will be further illustrated by, but is not intended to be limited to the following embodiments thereof shown in the accompanying drawings.

FIG. 1 is an elevation view partly in section of a former roller according to the invention.

FlGS. 2 and 3 are cross sections of the former rollers according to FIG. 1, in FIG. 3 the pusher bar being in its retracted position and in FIG. 2 in its pushed out position. FIG. 3 is a fragmentary view of the same cross section as shown in FIG. 2.

FIG. 4 is a fragmentary cross section of another embodiment of the former roller according to the invention in which the nozzles are arranged in the roller surface behind the pusher bar.

The former roller 1 consists of a casing 2 of sheet metal and end walls 3. The casing is stiffened by rings 4 arranged parallelly along the length of it. Further the former roller is provided with a hollow shaft 6 rotatably mounted in bearings and connected with a line 7 for pressurized air.

In the casing 2 there is an axial groove formed between two bars 10 fixed in the roller. In this groove, which extends radially into the roller, the pusher bar 11 is fitted movably in a radial direction. Some centimetres below the upper edge of the bar, which preferably has the same radius of curvature as the roller surface, the bar is provided with a number of grooves 14 from the front surface inwardly. From the depressions there are several borings through the bar wmch open in nozzles or openings 15 on the rear surface of the bar, and each depression 14 communicates, through a channel 19 in the bar, a pipe 2% and a flexible tube 22, with the hollow shaft 6 which in turn is connected with the pressurized air line 7. At the front surface of the bar 11 there is secured a plate covering the grooves 14- so as to form a cavity 18 in the pusher bar. The outer edge of plate 25 is some millimetres below the upper edge 12 of the bar 11, so as to form a groove 26 between the bar 11 and the bar 14) when the bar 11 is retracted. The outer edge of said plate 25 forms the bottom of the groove some millimetres below the upper edge 12 of the bar 11.

Bar 11 is connected to yoke 31 by bolt 36 and the yoke is secured to the piston rod 34 by threads 32. Piston rod 34 is connected with a piston (not shown) in cylinder 35 which in turn is connected with blocks 38 on casing 2 by lug 36 and bolt 37. The piston is movable in cylinder 35 in a closed space and divides this space into two parts, one of which being connected with the source of pressurized air through pipe 40, tube 41, pipe 42 and the hollow shaft 6, and the other of which being connected with the source of pressurized air via pipe 44, tube 45, pipe 46 and a pipe which is inserted in the hollow shaft 6 and connected with line 3. Pipe 42 may, if desired, be connected with a separate source of pressurized air. By valve timing gear known per se the admission of pressurized air may be controlled so that at appropriate periods of time pressurized air is admitted through the hollow shaft 6 to the lower part of the cylinder space and at the same time to cavity 18 and nozzles 15, which are closed by bar 16 when the bar is retracted. Cavity 13 may preferably be connected with its source of pressurized air via separate control means. Bar 11 is suitably actuated by at least two cylinders 35 although only one is shown in the FIGS. 1 and 2. On admission of pressurized air to said lower part of the cylinder space, bar 11 is pushed out so that nozzles 15 are uncovered at the peripheral surface of the roller and air is blown out therethrough. Then, the admission of air through shaft 6 is stopped and instead air is admitted from line 8 through the pipe (not shown) arranged in the hollow shaft 6 and thence to pipe 46 and tube 45, so that the piston in cylinder 35 is forced downwardly and bar 11 is retracted.

The apparatus works in the following way. When a suflicient number of sheets have been wound upon the former roller 1 while bar 11 is kept retracted in the groove, pressurized air is admitted through shaft 6 whereby bar 11 is pushed out. Due to the fact that the cardboard 59 is considerably weaker in the part covering groove 26 than in the parts resting on the roller surface it readily bursts at this groove along an axial line on the roller when bar 11 is pushed out. At its pushing out bar 11 lifts the edge fiap 51 of the cardboard due to the fact that the sheet is out along a line so much in front of the rear surface of the bar 11 as the groove 26 is in front thereof, and when the nozzles or openings 15 become uncovered the air issuing therefrom forces itself between sheet 50 and the surface of roller 1, thus facilitating the sheet to be detached from said surface. When bar 11 has been retracted the loosened cardboard is suitably taken down by hand, by a suitable grasper or with the aid of a so-called air-knife, i.e. a flat stream of air, arranged in an appropriate position. Occasionally the cardboard sheet loosens so easily that it may fall down by itself.

The embodiment illustrated in FIG. 4 is characterized in that nozzles 61 are arranged in one of the bars 10, Le. the bar behind pusher bar 11. Nevertheless it operates, in principle, as the embodiment described above. Bar 11 is of the sort which is provided with a furrow 26 in its peripheral edge 12. This sort can, of course, be used in other embodiments as well. The cardboard covering this furrow will be weaker than the rest of the cardboard and when bar 11 is pushed out the cardboard bursts in this zone along an axial line on the roller. Furrow 26 may be arranged along the medium line on the edge 12 of the bar 11 but it is preferably placed near the front surface of the bar so that the edge flap of the sheet overlaps the bar sufficiently in the way set forth above in connection with the embodiment according to FIG. 2 without necessitating a great width of the pusher bar.

We claim:

1. For use in a cardboard machine in which cardboard is formed by accumulating successive layers of relatively wet pulp on a rotatable forming roller: the combination comprising a rotatable forming roller having an axially extending radial groove opening through its peripheral surface; a pusher bar slidably mounted in said groove for movement between a position in which its outer edge is substantially flush with the peripheral surface of said roller and an extended position to lift the layers of pulp away from the peripheral surface of said roller; nozzle means having discharge openings along the trailing edge of said pusher bar and connected to a source of pressurized gas to discharge the gas, under pressure, substantially rearwardly from the pusher bar when the latter is at least partially extended beyond the peripheral surface of said roller; and means operable to sever the accumulated layers of pulp along a line parallel to and spaced forwardly from the tailing surface of said pusher bar to form a flap which is lifted by said pusher bar when the latter is projected from said slot; so that the gas discharged under pressure can enter between such flap and the peripheral surface of the roller to lift the formed cardboard from the surface of the roller.

2. The combination claimed in claim 1, in which the means for severing the accumulated pulp layers comprises a groove in the peripheral surface of the roller spaced forwardly from the tailing edge of the pusher bar, whereby a weakened portion of the accumulated pulp layers is formed in alignment with such groove for ready severing when the pusher bar is projected from said slot.

3. The combination claimed in claim 2, in which said groove is formed in the peripheral surface of said roller in advance of the leading edge of said pusher bar.

4. The combination claimed in claim 2, in which said groove is formed conjointly by the leading edge of said slot and the leading edge of said pusher bar which is spaced circumferentially from the leading edge of said slot.

5. The combination claimed in claim 1, in which the outer edge surface of said pusher bar has the same radius of curvature as the peripheral surface of said roller.

6. The combination claimed in claim 1, in which said nozzle means opens through the trailing surface of said pusher bar and is connected to a chamber in said pusher bar connected to a source of pressurized gas.

7. The combination claimed in claim 6, in which said nozzle means comprises a series of nozzles at the same radial spacing from the center of said roller and extending throughout the effective length of said pusher bar for simultaneous uncovering upon projection of said pusher bar from said slot.

8. The combination claimed in claim 6, in which said nozzle means comprises a series of nozzles extending through the effective length of said pusher bar and disposed at relative radial distances from the center of said roller such that said nozzles are progressively uncovered as said pusher bar is projected from said slot.

9. The combination claimed in claim 1, in which said slot comprises a pair of axially and radially oriented and circumferentially spaced bars; said nozzle means opening through the outer surface of the trailing one of said bars.

10. The combination claimed in claim 1, including fluid pressure actuator means within said roller and connected to said pusher bar to project and retract the latter.

11. The combination claimed in claim 1, including mechanical means connected to said pusher bar and to said roller for projecting and retracting said pusher bar.

12. The combination claimed in claim 1, in which said nozzle means are oriented to direct the discharged pressurized gas in a tailing direction and at an angle of from to with respect to a radial plane of said roller.

13. The combination claimed in claim 1, in which there are at least a pair of saidpusher bars radially reciprocably mounted on said roller and each having accumulated pulp severing means associated therewith.

References Cited in the file of this patent UNITED STATES PATENTS 750,746 Woodburn Jan. 26, 1904 1,186,018 Meisel June 6, 1916 2,105,707 Stanclitf Jan. 18, 1938 2,445,254 Winterburn July 13, 1948 2,523,183 Beall Sept. 19, 1950 2,742,965 Drummond Apr. 24, 1956 2,872,186 Raybuck Feb. 3, 1959 2,947,065 Moody et a1 Aug. 2, 1960 

1. FOR USE IN A CARDBOARD MACHINE IN WHICH CARDBOARD IS FORMED BY ACCUMULATING SUCCESSIVE LAYERS OF RELATIVELY WET PULP ON A ROTATABLE FORMING ROLLER: THE COMBINATION COMPRISING A ROTATABLE FORMING ROLLER HAVING AN AXIALLY EXTENDING RADIAL GROOVE OPENING THROUGH ITS PERIPHERAL SURFACE; A PUSHER BAR SLIDABLY MOUNTED IN SAID GROOVE FOR MOVEMENT BETWEEN A POSITION IN WHICH ITS OUTER EDGE IS SUBSTANTIALLY FLUSH WITH THE PERIPHERAL SURFACE OF SAID ROLLER AND AN EXTENDED POSITION TO LIFT THE LAYERS OF PULP AWAY FROM THE PERIPHERAL SURFACE OF SAID ROLLER; NOZZLE MEANS HAVING DISCHARGE OPENINGS ALONG THE TRAILING EDGE OF SAID PUSHER BAR AND CONNECTED TO A SOURCE OF PRESSURIZED GAS TO DISCHARGE THE GAS, UNDER PRESSURE, SUBSTANTIALLY REARWARDLY FROM THE PUSHER BAR WHEN THE LATTER IS AT LEAST PARTIALLY EXTENDED BEYOND THE PERIPHERAL SURFACE OF SAID ROLLER; AND MEANS OPERABLE TO SEVER THE ACCUMULATED LAYERS OF PULP ALONG A LINE PARALLEL TO AND SPACED FORWARDLY FROM THE TAILING SURFACE OF SAID PUSHER BAR TO FORM A FLAP WHICH IS LIFTED BY SAID PUSHER BAR WHEN THE LATTER IS PROJECTED FROM SAID SLOT; SO THAT THE GAS DISCHARGED UNDER PRESSURE CAN ENTER BETWEEN SUCH FLAP AND THE PERIPHERAL SURFACE OF THE ROLLER TO LIFT THE FORMED CARDBOARD FROM THE SURFACE OF THE ROLLER. 